The present invention relates to the field of power supplies, and more specifically, to reducing power consumption in power supplies for electronic devices requiring a non-commercial voltage supply, as is typical of mobile electronic products.
Individuals and corporations are becoming increasingly aware of their energy consumption and are actively seeking to reduce it. Whether the primary motivation is to reduce the size of a carbon footprint or save on energy costs, consumers are demanding more energy efficient and eco-friendly products from manufacturers. In our age of ubiquitous electronic devices, consumers and regulators are becoming increasingly aware of the energy costs of electronics. A common culprit of energy inefficiency is the so-called energy vampire. Common electrical devices, such as computers, televisions, and appliances require standby power and consume electricity even when the device is off. Standby power accounts for the power necessary to allow the device to maintain information even when it is off, respond to remote controls, or provide other functions. It also accounts for parasitic losses in the device. The power consumed in standby mode is comparable to the power consumed in active mode for many devices.
Many devices, such as laptop computers, cell phones, e-readers, and so-called tablets or slates, plug into an AC adapter that acts as a power supply and/or battery charger that converts the voltage of the commercially available power to one the electronic device uses. Many consumers leave such chargers plugged in after the device's battery has been charged, and even after the device is disconnected altogether. These idle chargers continue to consume energy even when they are no longer providing any valuable function. Arguably, the power consumed by adapters is entirely wasted since it provides no functional value to the owner other than the convenience of leaving the adapter plugged in. The EPA estimates that the power consumed by devices that are off or by chargers left plugged in amounts to approximately 45 billion kilowatt-hours of electricity per year and costs upwards of 3.5 billion dollars annually. Given these significant costs, the industry is focusing on ways to reduce the power consumed by the electronic devices they manufacture.